Process for treating napped fabrics



United States Patent PROCESS FOR TREATING NAPPED FABRICS George W.Lemieux, Swannanoa, N.C., assignor to Beacon Manufacturing Company, acorporation of Delaware No Drawing. Filed Sept. 21, 1964, Ser. No.397,676

3 Claims. (Cl. 8115.6)

This invention relates to a process for treating napped fabrics and moreespecially to a process for treating blanket fabric with a uniqueresinous composition that establishes and maintains the desiredresilience in the napped surface and also the desired softness.

Napped untreated blanket fabric may have a relatively high loftoriginally but this property will be diminished substantially throughnormal use of the blanket. Also, untreated blankets made of syntheticfibers will shed the napped fibers quite extensively when laundered.

Attempts to eliminate these disadvantages by treatment of the blanketfabric with the usual synthetic thermosetting resins alone are notsatisfactory because these resins render the fabric relatively stiff orharsh and boardy.

It has also been found unsatisfactory to treat the blanket fabric withthermoplastic type resins alone be cause they render the blanket mushyand give it a lifeless clammy feel.

In accordance with the present invention a blanket having a durable highloft, a soft feel and a lively resilient characteristic is obtained forthe first time. This heretofore unobtainable objective is made possibleby treatment of the fabric with a resinous composition that contains athermosetting, cellulose reactive component and a fiber coatingthermoplastic component, along with other constituents, admixed inproper proportions. Treatment of the synthetic fiber fabrics with thistype of composition also prevents the usual undesirable pilling andshedding of the synthetic fiber.

Treatment of the fabric with the above unique composition should becarried out in a manner to effect thorough impregnation and coating ofthe napped fibers. One requirement for this result is to have theuntreated napped fibers opened up and in upstanding position and tomaintain them in this position during the resin treatment and thefinishing operations.

A suitable mechanical arrangement for opening up and maintaining thenapped fibers in open upstanding position is described and claimed inGeorge W. Lemieux application Serial No. 335,307, filed] anuary 2, 1964,entitled Mechanisms and Method for the Production and Treatment ofNappedw Fabrics. While the' chemical process of this invention is notlimited to'aparticular mechanical arrangement, it has been found to workvery satisfactorily with. the apparatus disclosed in the above Lemieuxpatent application, and serves the chemical counterpart or complementthereof for producing the desired resilient, anti-pilling andanti-shedding blanket nap. In this preferred process/the blanket fabricis first napped on a napping drum, and thenapped fabric fe'd' overlead-in rolls covered with napping clothing to maintain the nappedfibers in upright position, and then fed on an endless conveyor member,through a closed chemical treating chamber and finally through a heatingchamber for drying the fabric and curing the resin impregnant andcoating, as illustrated, described and claimed in the above Lemieuxpatent application.

The chemical treating process of the present invention takes place inthe above mentioned closed chemical treating chamber and heatingchamber. The present application being directed to a chemical process,independently of any specific apparatus used therefor, does not requireillustration or detailed explanation of the equipment, but reference tothe illustrations and description in the above Lemieux application fordetails of one suitable form of apparatus may be made if desired.

For carrying out the chemical process of the present invention, achemical composition comprising the following materials may be used. Theparts of the individual ingredients forming the composition are given byweight of solids, unless otherwise indicated.

Chemical composition The procedure for mixing or compounding the aboveresinous formulation without catalyst is as follows:

The thermosetting resin and the glycol lubricant are mixed, and to thismixture is added the partially polymerized urea formaldehyde resin,water and urea. This mixture is stirred, and to it is added thethermoplastic copolymer. The pH of the resulting mixture is thenadjusted to a pH of about 6.5 to 7 by adding the required amount ofbuffering agent. These. mixing steps may all be carried out at normal orroom temperature.

Depending upon the specific properties desired in the treated blanketand the specific chemicals used, some of the components in the aboveresinous composition may be varied. For example, the partiallypolymerized urea formaldehyde resin may vary from approximately 5 to 15parts; the thermoplastic copolymer may vary from approximately 15 to 20parts; and the formaldehyde acceptor may vary from approximately 0 to 5parts. The amount of water added depends upon the desired viscosity forshipping and ultimate handling of the liquid resinous composition. Ifnecessary, a small amount, such as for example about 1% or less, of ananti-foam may be used to control foaming of the composition.

The above composition may be catalysedwith normal resin catalysts,suchas amine hydrochloride, magnesium chloride, maleic acid, etc.,typical formulas for which are as follows:

Amine hydrochloride catalyst Adjust pH to 3.5-4.0 with ammonia.

The selected resinous composition and catalyst are maintained separateduring storage and shipment, and are mixed just prior to use of thecomposition for treatment of the napped blanket cloth in accordance withthis invention.

In a typical operation carried out in accordance with this invention, afifty gallon batch of the resinous composition and catalyst is made upby mixing one hundred and twenty pounds of the liquid resinouscomposition, in approximately two-thirds volume of water, and addingfifteen pounds of the liquid catalyst and then bringing the total volumeto fifty gallons with water. This final mixture is applied in the formof a fine mist or fog onto both sides of a cellulosic fiber-containingnapped blanket fabric, as it passes through the above mentioned chemicaltreating chamber, this chamber being enclosed to maintain an atmosphereof the chemical in uniform, constant contact with the fabric, as itpasses through the enclosed chamber. The fog or mist of treatingchemical in this chamber penetrates the napped surfaces of the fabric toeffect a thorough impregnation thereof with the chemical and it alsoforms a coating of the chemical on the napped fibers.

The passage of the napped fabric through the chemical treating chamberabove described, is continuous and preferably constant and in a typicalexample may be at the rate of approximately 30 yards of the fabric perminute.

Promptly following treatment of the fabric in the treating chamber asabove described, the resulting wet, napped fabric is passed through aheating chamber, which is heated in a suitable manner, such as forexample with a flow of hot air through the chamber, or electricalheating units properly disposed in the chamber adjacent the path of themoving fabric. The speed of the fabric through this heating chamber andthe temperature thereof are adjusted so as to effect drying of thefabric and curing of the resin components in the above describedtreating composition. In a typical case, the temperature in the heatingchamber is maintained at approximately 330 F., and the speed of thefabric is approximately 30 yards per minute. During this drying andcuring step of the process, the conditions are such that thethermosetting resin component of the composition, e.g. the methylateddimethylol urea resin, and the partially polymerized urea formaldehyderesin, will crosslink with the cellulose of the treated fabric. Thesecomponents impart to the treated napped fabric the above describeddesired resilience, which the untreated fabric does not possess. This isparticularly true of the methylated dimethylol urea resin component, andthe partially polymerized urea formaldehyde resin component gives thefabric the desired hand.

The thermoplastic component of the resinous composition, forms theimportant function of coating the fibers and effecting cohesiontherebetween which enables the fibers to resist abrasion encounteredduring normal use of the blanket and to resist shedding of the napduring use and laundering of the blanket.

The napped fabric which may be processed in accordance with the presentinvention may be composed of any of the textile fibers or mixtures offibers, and the base fabric is usually a woven fabric although knittedor nonwoven fabric may be used for the napping and chemical processingtreatments. Typical examples of fibers which may be used in the fabricare cellulosic fibers, e.g. cotton and rayon; natural fibers, such aswool; blends of cellulosic fibers with synthetic fibers, such as nylon;the acrylics, such as Orlon, Acrilan and Zefran; and polyester fibers.

As above mentioned, it is important for the purposes of the presentinvention to use a resinous composition containing both thethermosetting resin component and the thermoplastic resin componentwhich cofunction to give the desired properties in the final blanket.The properties of durable high nap, resilience, resistance to pillingand shedding and at the same time, the desired soft hand, cannot beobtained :by use of either of these resin components without the other.

Various changes may be made in the above described chemicals,compositions, and procedures without departing from the scope of theinvention, as defined in the appended claims.

I claim:

1. A chemically treated napped cellulosic fabric having a high loft,permanent resilience, softness of hand and resistance to abrasion andshedding of the nap during use of the fabric and laundering thereof,said fabric having a surface of resilient upstanding napped fibers whichare impregnated and coated with a resinous composition consistingessentially of a thermosetting resinous component selected from thegroup consisting of dimethylol ethylene urea, methylated methylolmelamine, methylated dimethylol urea, and dimethylol triazone and athermoplastic resinous component selected from the group consisting ofvinyl ketone/styrene copolymers and butadiene/styrene copolymers, saidthermoplastic resinous component being present in an amount betweenapproximately onethird and one-half of the amount of the thermosettingcomponent, by weight, said resinous composition being cured and beingpresent in sufficient amounts to form an impregnant and a coating of thefibers throughout the napped surface of said fabric.

2. A product as defined in claim 1 wherein the napped fabric is ablanket.

3. A product as defined in claim 2 wherein the thermosetting resinouscomponent is cross-linked with the cellulosic components of the blanket.

References Cited by the Examiner UNITED STATES PATENTS 1,922,444 8/1933Libbey 117162 2,277,941 3/1942 Almy 260-852 X 2,446,806 8/1948 Bernard117-143 X 2,536,050 1/1951 Pluck 117139.4 2,731,368 1/1956 Fortess eta1. 117-139.4 2,765,287 10/1956 Aycock 117-139.4 X 2,864,093 12/1958Summer of a1. 117-140 X 3,096,524 7/1963 Mizell 117-139.4 X 3,197,7908/1965 Getchell 81 16 WILLIAM D. MARTIN, Primary Examiner. T. G. DAVIS,Assistant Examiner.

1. A CHEMICALLY TREATED NAPPED CELLULOSIC FABRIC HAVING A HIGH LOFT,PERMANENT RESILIENCE, SOFTENESS OF HAND AND RESISTANCE TO ABRASION ANDSHEDDING OF THE NAP DURING USE OF THE FABRIC AND LAUNDERING THEREOF,SAID FABRIC HAVING A SURFACE OF RESILIENT UPSTANDING NAPPED FIBERS WHICHARE IMPREGNATED AND COATED WITH A RESINOUS COMPOSITION CONSISTINGESSENTIALLY OF A THERMOSETTING RESINOUS COMPONENT SELECTED FROM THEGROUP CONSISTING OF DIMETHYLOLO ETHYLENE UREA, METHYLATED METHYLOLMELAMINE, METHYLATED DIMETHYLOL UREA, AND DIMETHYLOL TRIAZONE AND ATHERMOPLASTIC RESINOUS COMPONENT SELECTED FROM THE GROUP CONSISTING OFVINYL KETONE/STYRENE COPOLYMERS AND BUTADIENE/STYRENE COPOLYMERS, SAIDTHERMOPLASSTIC RESINOUS COMPONENT BEING PRESENT IN AN AMOUNT BETWEENAPPROXIMATELY ONETHIRD AND ONE-HALF OF THE AMOUNT OF THE THERMOSETTINGCOMPONENT, BY WEIGHT, SAID RESINOUS COMPOSITION BEING CURED AND BEINGPRESENT IN SUFFICIENT AMOUNTS TO FORM AN IMPREGNANT AND A COATING OF THEFIBERS THROUGHOUT THE NAPPED SURFACE OF SAID FABRIC.